Revision 6655

changed all occurences of "published" to "visible"   and of "unpublished" to "hidden"

also modified database.conf.dist   so that visible is aliased to "published".

thus the database reference remains "published" but everything else is changed.

Next project:  create an easy automatic upgrade of tables to change field name from 
"published" to "visible"  and then change back the database.conf.dist